Vent

ABSTRACT

A flood flaps vent for sealing a building crawlspace includes: (a) a vent box including open opposite front and rear ends forming a vent passageway in the vent box, the vent box including a top box portion and an opposite bottom box portion; (b) flexible flood flap hingably mounted to the vent box near the rear end of the vent box and constructed and arranged to permit the flexible flood flap to flex within the vent passageway to open the passageway; and (c) a grille that may be hingably mounted, the grille having openings therein for air and water flow through the grille, and positioned over the open front end of the vent box; the flood flap occluding the rear end of the vent box when it is in an at rest, home position. This simplified abstract is not intended to limit, and should not be interpreted as limiting, the scope of the claims.

This application is a continuation in part of application Ser. No.13/385,399 filed Feb. 17, 2012, in which Applicant claims priority.

FIELD OF THE INVENTION

The present invention relates to a crawlspace vent with flood flaps thatpermit flood waters to pass in and out of a sealed crawlspace under abuilding in the event of a flood, yet inhibit air flow through thesealed crawlspace the rest of the time.

BACKGROUND

Many builders and homeowners in the last decade are realizing theadvantages of sealing the crawlspace under their new construction, orconverting the crawlspace under an existing building to a sealedcrawlspace. With dehumidifiers operating in the crawlspace, usuallyunder the control of a humidistat, such advantages include reducedhumidity and a relatively constant temperature in the crawlspace, whichresult in lower heating and cooling bills for the building, reducedmold, fungus, and mildew under the building, and fewer problems fromsmall animals entering through the crawlspace. Conventional air ventsare disadvantageous with a sealed crawlspace, because dehumidifiersunder the building will not work as well with an influx of humid outsideair entering the crawlspace through conventional air vents.

However, houses and other buildings built in a flood-prone area requiresome sort of crawlspace venting to prevent the building walls fromweakening or collapsing during a flood event. Without vents that permitflood waters to flow in and out of the crawlspace under a building,hydrostatic pressure in the crawlspace can reach a break point beyondwhich the building walls may crumble. It has therefore been impossibleto seal a crawlspace in a building on a flood plain heretofore whilecomplying with government rules and regulations. Up to this point, therehave not been any cost-effective vents that obstruct air flow completelyand provide insulation, yet allow water to flow into and out of a sealedcrawlspace.

Buildings located in areas where flooding is a possibility are generallyrequired to have vents in the walls of their crawlspaces to allow floodwaters to flow in to and out of the crawlspace in order to relievehydrostatic pressures that could destroy the integrity of the walls. Inall buildings with crawlspaces, whether in a flood zone or not,crawlspace vents are used to allow air flow to avoid dampness under thebuilding, which can cause rotting, insect infestation, moisture buildup,etc. The new sealed crawlspace can be installed as a building is beingconstructed or retroactively. The sealed crawlspace provides a dry,clean and heating and air conditioning efficient building. The floodflaps vent opens to permit a flow of water in or out of the buildingwhen the water level outside (or inside) the building rises, therebyavoiding an excessive pressure differential to develop between theinterior and exterior of the building, as well as damage or failure ofthe building while maintaining a sealed vent when high water conditionsdo not exist.

Rules and regulations now require buildings with enclosed spaces locatedbelow defined flood plain levels to include automatic equalization ofinterior and exterior hydrostatic pressure caused by flood waters. Therules and regulations require buildings to be designed and built toallow flood water to move in and out of a building freely.Unfortunately, the vents developed for flood purposes cannot provide theinsulated and sealed conditions required by sealed crawlspacetechnology. A number of devices have been developed to reduce oreliminate the pressure differential that may develop between theinterior and exterior of a building.

The flood flaps vent of the present invention maintains a sealedcrawlspace environment by blocking air flow through the vent, yetpermitting water to flow in and out of the crawlspace freely during ahigh water event. In a building with flood flaps vents, hydrostaticpressure does not reach a break point and structural integrity of thebuilding is maintained.

SUMMARY OF THE INVENTION

The present invention is a vent with flood flaps for sealing acrawlspace under a building. The flood flaps vent comprises: (a) a ventbox portion including open opposite front and rear ends on either end ofa vent passageway in the vent box portion; (b) flexible flood flapextending across the open rear end portion of the vent box portion, thatis hingably mounted to the vent box so as to flex and/or pivot withinthe passageway, and (c) a grille assembly over the open front endportion of the vent box portion. The grille may be mounted so as topivot within the passageway. The flood flap substantially occludes therear end portion of the vent box portion when the flood flap is in an atrest, home position

Advantages of the flood flaps vent of the present invention include thefollowing: 1) allows building crawlspaces of buildings in flood plainsto be air sealed yet comply with state and federal codes for crawlspaceflood venting; 2) allows the homeowner to control humidity whileminimizing the threat of loss of integrity of the building walls in theevent of a flood; 3) the grille assembly on the front of the flood flapsvent presents an aesthetically pleasing appearance to passers by, helpsdeter vandalism, and retards the entry of animals and other vermin intothe crawlspace; 4) double or multiple flaps may be present in each floodflaps vent to help maintain the house's thermal insulation throughoutthe sealed crawlspace; 5) the passageway interior of the flood flapsvent is sized to help prevent flood water from flowing between thelayers of the building walls (e.g., block and brick) and causing waterdamage; and 6) the flood flaps vent is economical, especially whencompared to the costs for flood damage that may occur if it is notemployed.

DESCRIPTION OF THE DRAWINGS

A more complete understanding of the invention and its advantages willbe apparent from the following detailed description taken in conjunctionwith the accompanying drawings, wherein examples of the invention areshown, and wherein:

FIG. 1 shows a front perspective view of a flood flaps vent according tothe present invention;

FIG. 2 is a front elevation view of a flood flaps vent according to thepresent invention, shown during a flood event;

FIG. 3 is a rear perspective view of a flood flaps vent according to thepresent invention, shown with the flood flaps cut away for purposes ofillustration;

FIG. 4 is a rear perspective view of a flood flaps vent according to thepresent invention, shown without an outer flood flap for purposes ofillustration;

FIG. 5 is a side cross-sectional view of a flood flaps vent according tothe present invention, shown installed in a building wall vent;

FIG. 6 is a side cross-sectional view of a flood flaps vent according tothe present invention, shown with flood water flowing through the floodflaps vent out of the crawlspace;

FIG. 7 is a side cross-sectional view of a flood flaps vent according tothe present invention, shown with flood water flowing into thecrawlspace;

FIG. 8 is an enlarged side cross-sectional view of the flood flaps ventaccording to FIG. 5;

FIG. 9 is a side cross-sectional view of the flood flaps of the floodflaps vent according to FIG. 1;

FIG. 10 is a rear perspective view of a flood flaps vent according tothe present invention, shown with detached flood flaps;

FIG. 11 shows six alternate side views of a free edge of a flood flap ofa flood flaps vent according to the present invention; and

FIG. 12 is a rear perspective view of a flood flaps vent according tothe present invention, shown with a single flood flap sheet.

FIG. 13 shows a front perspective view of another embodiment of a floodflaps vent according to the present invention;

FIG. 14 is a rear perspective view of the flood flaps vent of theembodiment shown in FIG. 13, shown with detached flood flaps and adetached grille.

FIG. 15 is an enlarged side cross-sectional view of the flood flaps ventof the embodiment shown in FIG. 13.

FIG. 16 is partial, sectioned view of the embodiment of FIG. 13 showingthe grille mounted with a hinge that permits pivoting of the grillewithin the passageway of the vent box and relative to the vent box.

FIG. 17 is a side cross-sectional view of a flood flaps vent of theembodiment shown in FIG. 13, shown with flood water flowing through theflood flaps vent out of the crawlspace.

FIG. 18 is a side cross-sectional view of a flood flaps vent accordingto the embodiment shown in FIG. 13, shown with flood water flowing intothe crawlspace.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, like reference characters designate likeor corresponding parts throughout the several views. Also, in thefollowing description, it is to be understood that such terms as“front,” “back,” “within,” and the like are words of convenience and arenot to be construed as limiting terms. Referring in more detail to thedrawings, a device embodying the principles and concepts of the presentinvention and generally designated by the reference numeral 10 will nowbe described.

Turning first to FIGS. 1, 2, and 5, a flood flaps vent 10 fits closelyinto a correspondingly sized vent space 13 in a building wall 12adjacent a crawlspace 14 under the building 11. The flood flap vents 10are permanently fixed in the foundation walls of the building at anelevation above ground level. Flood flaps vents 10 are spaced apartaround the lower part of a house or other building, usually about onevent for every hundred square feet or so of crawlspace (though thisnumber varies). Often the front of the flood flaps vents 10 and thefront wall of the house or other building can be seen from the street,with the flood flaps vents 10 all being at generally the same level onthe building. As illustrated in FIG. 2, the decorative grills 20 on thefront of the flood flaps vents 10 present a pleasing appearance from thestreet. As shown in FIG. 5, the crawlspace wall may include a brick wall12 b at the front of the flood flaps vent 10, and cement blocks 12 a atthe rear, often with spaces between.

The building 11 is a house, an office building, a warehouse, or anyother type of building with a crawlspace. The flood flaps vents 10 areplaced in the walls 12 of the crawlspace under a new building underconstruction, or they are retrofitted into the walls 12 of an existingbuilding once the old vents have been removed. The building 11 may bedesigned and built with a sealed crawlspace under it, or an existingspace under a building can be sealed to form a sealed crawlspace 14. Theflood flaps vents 10 can be placed in all four walls 12 of a smallhouse, for example, or just in a front wall and an opposite back wall ofa building.

One or more dehumidifiers, which are usually controlled by a humidistat,are often placed inside the crawlspace 14 to keep the humidity at acontrolled level. Flood flaps vents 10 have been found to help maintaina constant temp in the 60's (degrees Fahrenheit) within the crawlspace.Without meaning to be bound by theory, it is believed that flood flapsvents help control temperature and therefore heating and airconditioning costs in the home or other building 11 above the crawlspace14. Growth of mold, fungus, and mildew is controlled in a sealedcrawlspace equipped with flood flaps vents 10 and dehumidification, andwood under the building is less likely to rot or be damaged by insects.The flood flaps vents 10 largely discourage small animals, such as rats,opossums, cats, raccoons, moles, snakes, lizards, and some insects, fromentering the sealed crawlspace.

As illustrated in FIGS. 1, 2 and 5, the flood flaps vent 10 includes:(a) a substantially box-shaped vent box portion 15 with opposite openends 18, 19 on either end of the vent passageway 22; (b) flood flap 16extending across the open rear end 18 of the vent box portion 15; and(c) a grille assembly 17 at the open front end 19 of the vent boxportion 15. The opposite open ends 18, 19 of the vent box portion 15 arepreferably each substantially rectangular-shaped. The front or rear endportion is the front or rear area, respectively, adjacent the end.

Crawlspace walls are most often brick and/or cement block. The vent boxportion 15 is normally the height of a cement block, since it frequentlyreplaces a cement block in a crawlspace wall. In an existing structure,a cement block is removed from a cement block building wall 12 adjacentthe crawlspace and a flood flaps vent 10 is inserted into the vent spaceand sealed in.

The grille assembly 17 includes the decorative grille 20 across itsfront end 19 and preferably a screen 21, which may be positioned infront of or behind the grille 20, or embedded in the grille. The grilleassembly 17 is preferably recessed about one (1) inch from the face ofthe house wall and presents a pleasing appearance to passersby. Thescreen 21 and grille 20 function to prevent mice, snakes, moles, etc.,as well as larger animals, such as cats and rats, from entering thecrawlspace to nest, eat, and breed. The screen 21 also traps debris andprevents it from entering the crawlspace. Although any suitable type ofscreen may be used, the screen 21 preferably has a grid of open squares,each with a grid size of up to about ½ inch for preventing debrisintrusion yet permitting water to flow freely through it. The screen 21is preferably part of the grille assembly 17 and is attached to, or ismolded to, a front or rear of the grille, or is the molded or insertedinside the vent passageway 22 adjacent and behind the grille 20. Thefront face of the screen 21 preferably contacts the rear of the grille20. The openings in the grille 20 are larger than the squares in thescreen 21. The screen 21 is preferably made of aluminum or othermetallic or fabric to prevent insects, other vermin, or debris fromentering the crawlspace 14 under normal or flood conditions.

Alternatively, in the case of a retrofit, the grille 20 or the entiregrille assembly 17 can be removed from the flood flaps vent 10, which isthen glued or otherwise attached to a grille of an existing house.Preferably, however, the grille assembly is hingably mounted to the ventas described herein.

By “sealed crawlspace” herein is meant a space under a building withwalls that have been segregated from the outside elements. Thecrawlspace is not necessarily hermetically sealed, just closed in aswell as is feasible, as by adding insulation, sealing the floor andwalls, and adding dehumidifiers to keep the crawlspace dry. By “sealingthe crawlspace” herein is meant that, along with these other sealingmeasures taken, the flood flap vent 10 with its flood flap 16 helps toseal the building crawlspace 14.

By “flood plains” herein is meant flat or nearly flat land adjacent tooceans, streams or rivers, but also any land that is periodicallyexposed to flooding, even places where floods occur some 30-100 yearsapart.

With attention to FIGS. 1 through 5, the vent box portion 15 iscomprised of two generally parallel side wall portions 23 connected attheir bottom edges to opposite edges of a bottom box portion 24, andalong their top edges to the opposite edges of a top box portion 25. Allof the four portions 23-25 are generally rectangular in shape. The ventbox portion 15 is preferably generally rectangular in cross-section. Thevent box portion 15 is preferably one-piece and made of any suitablematerial, such as plastic or polyvinylchloride, most preferably moldedrecycled plastic The side wall portions 23 are preferably same sized andparallel to one another, and at right angles to the top and bottom boxportions 24, 25. The top and bottom box portions 24, 25 are preferablysame-sized and parallel to one another, and at right angles to the sidewall portions 23. The outside corners of the vent box 15 are preferablysquare, though they may be rounded.

Although its size may vary, the vent box 15 is most preferably about 12inches deep, its size being determined by the size of a cinder block,since the flood flaps vent 10 replaces one cinder block. The flood flapsvent 10 is preferably (but not limited to) about 8 inches by 16 inchesby 12 inches. A second size is about 16 inches by 16 inches by 12inches. In the case of a brick building wall, which is generally thinnerthan a cinder block wall, a rear part of the flood flaps vent 10 simplysticks out into the crawlspace 14.

With continued attention to FIGS. 1 through 5, while the front end 19 ofthe vent box 15 is covered by the grille assembly 17, the open rear end18 is covered by, and preferably two or three, flood flaps 16. Withoutmeaning to be bound by theory, it is believed that one flood flap 16 issufficient for use in temperate climates. In a majority of climates, twoflood flaps 16 covering the rear end 18 of the box 15 are optimal.Double flood flaps 16 provide thermal insulation that is consistent withthe insulation of the interior crawlspace walls. (Insulation isinstalled on the crawlspace walls as part of the sealing process.) Wherewinter or summer temps are consistently excessive (e.g., extremenorthern climes, desert locales), three flood flaps 16, one behind andparallel to the next, are preferred for the additional insulation theyprovide. Three flood flaps help regulate the temperature in the sealedcrawlspace 14 and yet permit flood waters to pass through the crawlspace14 in the event of a flood.

Each flood flap 16 extends down substantially vertically from the topbox portion 25 of the vent box 15, as seen in FIGS. 3-10. Where theflood flaps vent 10 has two flood flaps 16, the top box portion 25includes two parallel flap slots 27 that extend almost from one sideedge to almost the opposite side edge of the top box portion 25 over theotherwise open rear end 18 of the vent box 15. The flap slots 27 arepreferably rectangular-shaped (looking down from above), with short sideedges. The rearmost slot 27 a is preferably about an inch or two fromthe rear end 18 of the flood flaps vent 10 for strength.

As seen in FIGS. 8-10, each flood flap 16 preferably includes athickened upper flap wedge 28 that extends along the top of each floodflap 16. The upper flap wedge 28 is preferably generally triangular incross-section, as seen in FIGS. 9 and 10. To assemble the flood flapsvent 10, the body of each flood flap 16 slides down through the flapslot 27 as seen in FIG. 10. The flap slot 27 is also generallytriangular, or wedge-shaped, in cross-section, so that the flap wedge 28catches in the flap slot 27, as seen in FIG. 9. Thus, the flood flap 16hangs in the flap slot 27, suspended by the flap wedge 28 in the flapslot 27. The flood flap 16 need not be glued into place within the floodflaps vent 10.

The flood flap 16 is the about the same size as the passageway 22 at therear end 18 of the vent box 15. The other three side edges 30, 31 of thegenerally rectangular-shaped flood flap 16 are preferably sharp-edged,as seen in FIGS. 8-10. The three free edges 30, 31 of the flood flap 16preferably contact the inside of the vent box 15. The flood flaps 16 arepreferably the exact size of the rear end opening so as to prevent airfrom passing through from the vent passageway 22 into the crawlspace 14.The flood flaps 16 may be slightly larger than than the channels in thevent box so that they positively contact the sides and bottom of thevent box, while still be capable of deflection away from the vent boxunder pressure from, for example, flood water.

The vent box portion 15 preferably includes a bottom channel, andpreferably two wall flap channels 29, formed into the inside faces ofthe two opposite side wall portions 23, and the bottom box portion 24between them, in the area of the box rear end 18. The term “side flapedges” herein is meant to include the side edges 30 and the bottom edge31 of the flood flap 16. The side flap edges 30 of each flood flap 16fit into the opposite side sections of the corresponding flap channel29. The bottom flap edge 31 of the flood flap 16 fits into the centralsection of the flap channel 29, as seen in FIG. 9. The side sections ofthe flap channel 29 are continuous with the central section of that flapchannel. The three free edges 30, 31 of the outer flood flap 16 a fitinto the outermost flap channel 29 a, and the three free edges 30, 31 ofthe inner flood flap 16 b fit into the innermost flap channel 29 b. By“free” is meant that the edges 30, 31 are not attached to any structure,which permits the flood flap 16 to flap in and out with water enteringor exiting the flood flaps vent 10 during, for example, a flood.

The flap channel 29 helps maintain a home position for the free edge 30,31 of the flood flap 16 that fits into the flap channel 29, protectingthe flood flap from windy conditions. Even though its three flap edges30, 31 rest in the flap channel 29, the flexible flood flap 16 iscapable of swinging from the top flap edge, which is preferably a flapwedge 28, in the vent passageway 22. The base of the flap channel 29 ispreferably curved as seen in FIGS. 3, 5 and 9 in order to facilitatemovement of the flood flap edges 30, 31 into and out of the flap channel29. The base of the flap channel 29 is less preferably substantiallyflat with relatively straight sides parallel to one another borderingthe channel base. The free flap edges 30, 31 in the flap channels 29help seal the rear vent opening.

The flood flaps 16 are made of a durable material, such as rubber orvinyl sponge, that is flexible enough to resist air flow, thick enoughto provide insulation, and strong enough to keep rodents and othervermin out, yet allow water flow under flood conditions. The flood flapmaterial is preferably a molded, spongy material with a non-porous,semi-rigid skin sealed to the spongy material. It may be buoyant so thatthe body of the flood flap 16 is easily pushed upward by flood waters.Air bubbles are preferably entrained (suspended) in the flood flaps (seeFIG. 9) for buoyancy. If a flood flaps vent 10 is already in acrawlspace wall, the material is flexible enough to permit a flood flap16 to be replaced from inside a vent box 15, if necessary on rareoccasions. To do so, the upper flap wedge 28 at the top of the floodflap 16 is squeezed, inserted into the flap slot 27, and released. Thethree side edges 30, 31 of the body of the flood flap 16 find a home inthe corresponding flap channel 29, which is next to and below them. Whenthe flood flaps 16 are in the substantially vertical, resting position(steady state), the side edges 30, 31 of the body of the flood flap 16are seated in the corresponding flap channel 29.

Although the thickness of the flood flap 16 may vary, it has been foundherein that a preferred thickness of between about ¼ and ½ inch isoptimal for providing insulation. In their vertical, at rest positions,the inner flood flap 16 b is not in contact with the outer flood flap 16a. Importantly, the flood flaps 16 are preferably between about ½ inchand about two inches (most preferably about an inch) apart so the airspace between them provides additional insulation (see FIG. 5). Theinsulating flood flaps 16 help to seal the crawlspace. The width of theflap wall channel 29 is preferably about twice the thickness of theflood flap 16 in order to help the flood flap 16 slide into home(resting) position in the wall channel 29.

Alternatively and less preferably, the upper edge of the flood flap 16is attached within its flap slot 27 in the top box portion 25. The upperflap edge 28 is less preferably squared in a conventional manner, orsharp-edged like the other three, unattached flap edges 30, 31 asdescribed herein. To insert the upper flap edge in the flap slot 27 whenthe flood flaps vent 10 is being made, the upper flap edge is squeezed,inserted into the flap slot 27, and released. Since it is made of afoam-like material, the upper flap edge expands back out again once itis inserted, which holds it in the flap slot 27. This is anotheradvantage of the flood flap 16 being made of sponge vinyl or the like.Once it is in the flap slot 27, the upper edge of the flood flap 16 maybe attached in the slot, as by gluing.

The three (free) edges 30, 31 of the flood flap 16 are less preferablysubstantially squared off, or flat. They preferably have a sharp,tapered edge shape, though, for optimal functioning. As seen in FIGS. 8,10, and 11, the unattached edges 30, 31 preferably have the sameshape/appearance as one another, and one of six alternate shapes. Movingdown from the upper left of FIG. 11, the free edge 30 or 31 is: rounded35, with the round at the center of the edge 30, 31; knife-edged 36(preferred); or pointed 37. Moving down from the upper right of FIG. 11,the free edge 30 or 31 can be an off-center rounded edge 38 (mostpreferred); an off center knife edge 39; or a blade edge 40. It has beenfound herein that these sharper edges 35-40 glide more easily into andout of the flap channel 29, permitting the flaps to quickly find thehome (at rest) position and helping to seal the flood flaps vent 10.

Flood events are mercifully few and far between in most places. However,when flood waters do rise, incoming flood water 34 pushes the floodflaps 16, as seen in FIG. 7. The flood water 34 surges through thegrille 20 and screen 21 at the front end 19 of the flood flaps vent 10,through the vent passageway 22, by the flood flaps 16, and out the rearend 18 of the vent box 15. As the water rushes by the flexible floodflaps 16, it pushes the bodies of the flood flaps 16 a, 16 b up and outof the way. (By “bodies of the flood flaps” herein is meant all but thetop edges of the flood flaps.) The flexed, sideways “L” shape of theflood flaps 16 seen in FIGS. 6 and 7 is their open “flood position”(versus their generally vertical, closed, at rest position). The upperflap wedges 28 hold the flood flaps in the flap slots 27, so the floodflaps 16 are not pulled out of the flood flaps vent 10. The flood flaps16 do not impede the rush of water into or out of the crawlspace 14.Since the flood flaps 16 are not blocking the rear end vent opening, thehydrostatic pressure under the building is unlikely to build, so it isless likely that the building walls 12 will be weakened or toppled bythe flood event.

As seen in FIG. 6, flood water 34 escaping from the crawlspace 14 passesthrough the open rear end 18 of the flood flaps vent 10, past the floodflaps 16, through the vent passageway 22, through the screen 21 andgrille 20 of the grille assembly 17 and out the open front end 19 of theflood flaps vent 10. The flood flaps 16 are preferably separated frombut close to one another, and close to the rear end 18 of the vent box15, and the flood flaps vent 10 is sufficiently long to accommodate thebody of the flood flaps 16, so that the bottom ends 31 of the floodflaps 16 will not push up against the grille assembly 17 during a floodevent. (By “body” of the flap is meant all but the top edge 28.) Doubleflood flaps 16 are preferably between about ½ inch and about two inchesapart, most preferably about one inch apart from one another, in a floodflaps vent 10.

In a less preferred flood flaps vent with three flood flaps 16, the ventbox potion 15 is sufficiently long (deeper) to accommodate the length ofthe innermost flood flap 16. The triple flap vent has threesubstantially parallel flap slots 27. At rest, the three flood flaps 16,which hang down into the passageway 22, are all substantially parallelto one another, resembling the double flap shown in FIG. 10, but with anadditional flap slot 27 adjacent the innermost slot 27 and a third floodflap 16 c in the flap slot behind the second flap 16 b.

The flood flap material is flexible enough to be moved in eitherdirection (in as in FIG. 6 or out as in FIG. 7) by slight waterpressure. The sturdy flood flaps 16 are sufficiently flexible to returnto their vertical, “sealed”, resting, home position (see FIG. 5) and dryout once the flood subsides. The flood flaps vent 10 is useful for thosebuildings in flood plains or other locations exposed to the possibilityof high water (e.g., during hurricanes, dam breaks), such as buildingsby rivers, creeks, lakes, the ocean, or downstream from dams. The lengthand height of the flood flap 16 is approximately the length and heightof the vent passageway interior.

For some applications, such as garage walls where horizontal space islimited, two flood flaps vents 10 can be stacked on top of one anotherin place of two stacked cinder blocks in a wall. Homeowners aresealing/insulating their garages more frequently now, for example, wherethey are storing furniture, documents, sports equipment, musicalinstruments, etc. in their garages and therefore want them temperaturecontrolled.

In FIG. 12, a single, wrap-around flood flap 32 is employed rather thantwo separate flood flaps 16 as described above. The less preferredsingle flood flap sheet 32 is about twice the height of two shorterflood flaps 16, with an additional, continuous, center flood flap piece33 that loops through the parallel flap slots 27 in the top box portion25 of the vent box 15. Thus, the single flood flap sheet 32 hangs overthe piece of the top box portion 25 between the flap slots 27 like aquilt over a quilt rack. One end portion of the single flood flap sheet32 hangs behind the other (like a double flap). The length of the singleflood flap 32 is the same as the shorter flood flaps 16 describedhereinabove. The bottom flap edges 31 of the single flood flap 32, whichare actually opposite ends of the single flood flap 32, preferablycontact the inside bottom box portion 24. In the resting, home position(see FIG. 12) then, each end portion of the single flood flap 32 blocksthe vent passageway 22. Otherwise, the vent box 15 and grille assembly17 of this flood flap vent 10 b are as described herein.

Thus, the flood flaps vent 10 b seen in FIG. 12 includes: (a) a vent boxportion 15 with opposite open front and rear end portions 18, 19 oneither end of a vent passageway 22 in the vent box portion 15, the ventbox portion 15 including a top box portion 25 and an opposite bottom boxportion 24, the top box portion 25 including two substantially parallelflap slots 27 in a rear end portion 18 of the vent box portion 15, witha section of the top box portion 25 between the two flap slots 27; (b) asingle flexible flood flap sheet 32 comprising a center flood flap piece33 continuous with two same-sized end flap portions on either side ofthe smaller center flood flap piece 33, the center flood flap piece 33contacting an upper surface of the section of the top box portion 25between the two flap slots 27, the end flap portions each hanging downfreely from one of the flap slots 27, the end flap portions occludingthe rear end portion 18 of the vent box portion 15; and (c) a grilleassembly 17 over the open front end portion 19 of the vent box portion15.

The vent box portion 15 of the single sheet flood flaps vent 10 b ofFIG. 12 preferably includes two opposite side wall portions 23, the topbox portion 25 and the bottom box portion 24 being connected by the twoopposite side wall portions 23. When the single flood flap sheet 32 isin the resting position, bottom flap edges 31 of each end flap portioncontact an inside surface of the bottom box portion 24, and oppositeside flap edges 30 of each end flap portion contact an inside surface ofone of the side wall portions 23. This flood flap vent 10 b may or maynot include flap channels 29 as described herein. One end portion of thesingle flood flap sheet 32 hangs behind the other, occluding the ventpassageway 22. An underside of the center flood flap piece 33 isattached, as by gluing, to the upper surface of the top box portionpiece between the flap slots 27. Only the center flood flap piece 33 isvisible from the top of the flood flaps vent 10 b. The bottom and sideflap edges 30, 31 of the single flood flap sheet 32 are preferably sharpas seen in FIG. 11 as described herein.

In another embodiment, the grille connects to the vent box by a hinge orpivot point. The vent box may otherwise be constructed according to theembodiments of the invention set forth herein. The grille may have astructure as described above, except that it is mounted to the vent boxin a manner that lets the grille pivot relative to the vent box, whichincludes the embodiment as shown in FIGS. 13-18 and described herein.

The preferred grille has openings that provide a decorative look, butthe vent box also provides a barrier that deters large objects frompassing through the grille. As disclosed above, the grille may alsocomprise a screen or similar mesh that permits air flow, but deterssmaller objects and animals from passing through the grille. The grille,especially when used with a screen or similar mesh, may collect objectsthat ultimately obstruct water flow through the grille. For example, ifflood water flows through the passageway, the flood water may comprisedebris such as leaves or other plant materials, or litter. The grilleacts as a filter, and the debris is trapped by the grille. The debrismay materially obstruct the flow of water through the grille, andtherefore, obstruct the flow of water through the vent box.

An embodiment of the invention includes a grille that is hingablymounted on one side of the grille to allow the grille to swing or pivotrelative to the vent box and within the passageway to permit water toflow through the passageway. As shown in FIG. 13, and according to oneembodiment of the invention, the grille is hingably mounted by a hinge44 to a top box portion. The grille is generally rigid as describedabove, but may have a hinge or pivoting member 44 that connects one sideof the grille to the vent box as shown in FIGS. 15 and 16.

In one embodiment, the hinge 44 may include a thickened wedge 41 thatextends along the top of the grille. The wedge may be generallytriangular in cross-section, as seen in FIGS. 15-18. The grille mayslide through the slot 48. The slot is also generally triangular, orwedge-shaped, in cross-section, so that the wedge catches in the slot inthe vent box, such as at the top of the vent box. Thus, the grille hangsin the slot, suspended by the wedge in the slot. The hinge need not beglued into place within the vent box.

The grille is substantially the same size as the passageway 22 at thefront end 18 of the vent box 15. The other three side edges of thepreferred generally rectangular-shaped grille are free, except asfurther described, to permit the grille to pivot and swing within thepassageway. The three free edges of the grille leave very little space,and preferably no more than 1 mm, between the edges of the grille andthe interior floor and side walls, respectively, of the vent box, whileallowing the grille to pivot and swing according to the goals of theinvention.

A grille stop 42 is provided to prevent the grille from pivoting andswinging unless and until substantially pressure is applied to thegrille, since in normal use pivoting and swinging of the grille is notdesired. Pressure from moving flood water will typically be at least13-18 lbs per square inch, and the stop is preferred to be constructedand arranged to hold the grille in the “home” position until thispressure is reached.

The grille stop may be positioned near the front end of the vent boxportion, and extending from the bottom box portion and/or the interiorside wall portions. The grille stop may be formed by spaced apart andraised members 42 that are raised above the bottom box portion and/orthe interior side wall portions of the vent box, and the raised members42 are positioned to receive the edges of the grille between the spacedapart and raised members 42 when the grille is in the at rest, homeposition. The grille stop receives and seats the edges of the grillebetween the raised members 42 when the grille is in the at rest, homeposition, as shown in FIG. 15. In another embodiment, a plurality ofspaced apart and raised members 42 are raised above the bottom boxportion and/or the interior side wall portions of the vent box, and thespaced apart and raised members are positioned to receive the edges ofthe grille between the spaced apart and raised members when the grilleis in the at rest, home position. In yet another embodiment, one or moreof the unattached edges of the grille are retained within a channelformed in the side wall portions and/or the bottom box portion of thevent box when the grille is in the at rest, home position.

In the embodiment of the vent box shown in FIGS. 17 and 18, the grillebreaks out of the grille stop in response to water pressure. Movement ofthe grille in these figures away from the “home” position is seen. Thisembodiment is compared with the embodiment of FIGS. 6 and 7 with regardto movement of the grille.

From the foregoing it can be realized that the described device of thepresent invention may be easily and conveniently utilized as a floodflaps vent for sealing a crawlspace under a building. It is to beunderstood that any dimensions given herein are illustrative, and arenot meant to be limiting.

While preferred embodiments of the invention have been described usingspecific terms, this description is for illustrative purposes only. Itwill be apparent to those of ordinary skill in the art that variousmodifications, substitutions, omissions, and changes may be made withoutdeparting from the spirit or scope of the invention, and that such areintended to be within the scope of the present invention as defined bythe following claims. It is intended that the doctrine of equivalents berelied upon to determine the fair scope of these claims in connectionwith any other person's product which fall outside the literal wordingof these claims, but which in reality do not materially depart from thisinvention. Without further analysis, the foregoing will so fully revealthe gist of the present invention that others can, by applying currentknowledge, readily adapt it for various applications without omittingfeatures that, from the standpoint of prior art, fairly constituteessential characteristics of the generic or specific aspects of thisinvention.

What is claimed is:
 1. A vent for sealing a building crawlspace, thevent comprising: (a) a vent box comprising a front end and a rear endlocated at opposite ends of a vent passageway in the vent box portion,the vent box comprising a top box portion, a bottom box portion, and twoside wall portions that surround the vent passageway; and (b) a flexibleflood flap extending across and covering rear end of the vent box, witha side of the flexible flood flap hingably connected to the vent boxnear the rear end of the vent box, with other sides of the flexibleflood flap being unattached, the flexible flood flap constructed andarranged to flex within the vent passageway; wherein the flexible floodflap substantially occludes the rear end of the vent box portion whenthe flexible flood flap is in an at rest, home position, and flexesunder pressure to open the passageway.
 2. The vent for sealing abuilding crawlspace according to claim 1, further comprising a grille,the grille comprising a plurality of openings therein, the grillepositioned near the front end of the vent box and covering ventpassageway near the front end of the vent box, the grille hingablymounted to the vent box and the grille constructed and arranged to pivotwithin the vent passageway.
 3. The vent for sealing a buildingcrawlspace according to claim 1, wherein the top box portion of the ventbox comprises a flap slot near the rear end of the vent box, and whereinthe edge of the flexible flood flap that is hingably connected to thevent box is inserted into the flap slot and forms a hinge for thehingably connected flexible flood flap.
 4. The vent for sealing abuilding crawlspace according to claim 2, wherein the top box portion ofthe vent box comprises a flap slot near the rear end of the vent box,and wherein the edge of the flexible flood flap that is hingablyconnected to the vent box is inserted into the flap slot and forms ahinge for the hingably connected flexible flood flap.
 5. The vent forsealing a building crawlspace according to claim 1, the vent box furthercomprising a flap channel in the rear end of the vent box portion,wherein the flap channel receives and seats therein an unattached edgeof the flexible flood flap when the flexible flood flap is in the atrest, home position.
 6. The vent for sealing a building crawlspaceaccording to claim 2, the vent box further comprising a flap channel inthe rear end of the vent box portion, wherein the flap channel receivesand seats therein an unattached edge of the flexible flood flap when theflexible flood flap is in the at rest, home position.
 7. The vent forsealing a building crawlspace according to claim 1, wherein the flexibleflood flap is substantially rectangular in shape and comprises threeedges that are unattached, the vent box further comprising a flapchannel in the rear end of the vent box portion, wherein the flapchannel receives and seats therein an unattached edge of the three edgesthat are unattached, when the flexible flood flap is in the at rest,home position.
 8. The vent for sealing a building crawlspace accordingto claim 2, wherein the flexible flood flap is substantially rectangularin shape and comprises three edges that are unattached, the vent boxfurther comprising a flap channel in the rear end of the vent boxportion, wherein the flap channel receives and seats therein anunattached edge of the three edges that are unattached, when theflexible flood flap is in the at rest, home position.
 9. The vent forsealing a building crawlspace according to claim 1, wherein the flexibleflood flap comprises three edges that are unattached, wherein the threeunattached edges of the flexible flood flap are each seated in acorresponding flap channel formed in the vent box when the flexibleflood flap is in the at rest, home position.
 10. The vent for sealing abuilding crawlspace according to claim 2, wherein the flexible floodflap comprises three edges that are unattached, wherein the threeunattached edges of the flexible flood flap are each seated in acorresponding flap channel formed in the vent box when the flexibleflood flap is in the at rest, home position.
 11. The vent for sealing abuilding crawlspace according to claim 1, further comprising a secondflexible flood flap, positioned near the rear end of the vent box. 12.The vent for sealing a building crawlspace according to claim 2, furthercomprising a second flexible flood flap, positioned near the rear end ofthe vent box.
 13. The vent for sealing a building crawlspace accordingto claim 1, further comprising a second flexible flood flap positionednear the rear end of the vent box and substantially parallel to theflood flap, the vent box, the vent box further comprising a flap channeland a second flap channel near the rear end of the vent box portion,wherein the flap channel receives and seats therein an unattached edgeof the flexible flood flap when the flexible flood flap is in the atrest, home position, and the second flap channel receives and seatstherein an unattached edge of the second flexible flood flap when thesecond flexible flood flap is in the at rest, home position.
 14. Thevent for sealing a building crawlspace according to claim 2, furthercomprising a second flexible flood flap positioned near the rear end ofthe vent box and substantially parallel to the flood flap, the vent boxfurther comprising a flap channel and a second flap channel near therear end of the vent box portion, wherein the flap channel receives andseats therein an unattached edge of the flexible flood flap when theflexible flood flap is in the at rest, home position, and the secondflap channel receives and seats therein an unattached edge of the secondflexible flood flap when the second flexible flood flap is in the atrest, home position.
 15. The vent for sealing a building crawlspaceaccording to claim 3, wherein the upper edge of the flexible flood flapis substantially wedge-shaped, the flap slot being correspondinglyshaped.
 16. The vent for sealing a building crawlspace according toclaim 4, wherein the upper edge of the flexible flood flap issubstantially wedge-shaped, the flap slot being correspondingly shaped.17. The vent for sealing a building crawlspace according to claim 2,wherein the grille comprises a frame having openings therein, and ascreen positioned behind and connected to the grille.
 18. The vent forsealing a building crawlspace according to claim 1, wherein, when theflexible flood flap is in the at rest, home position, opposite sideedges of the flexible flood flap fit into a corresponding flap channelin the inside side wall portions of the vent box, and a bottom edge ofthe flexible flood flap fits into a central flap channel in an inside ofthe bottom box portion of the vent box, the three sections of the flapchannel being contiguous with one another.
 19. The vent for sealing abuilding crawlspace according to claim 2, wherein, when the flexibleflood flap is in the at rest, home position, opposite side edges of theflexible flood flap fit into a corresponding flap channel in the insideside wall portions of the vent box, and a bottom edge of the flexibleflood flap fits into a central flap channel in an inside of the bottombox portion of the vent box, the three sections of the flap channelbeing contiguous with one another.
 20. The flood flaps vent according toclaim 1, wherein the flexible flood flap comprises a plurality of airbubbles that are entrained in the flexible flood flap material forbuoyancy.
 21. The flood flaps vent according to claim 2, wherein theflexible flood flap comprises a plurality of air bubbles that areentrained in the flexible flood flap material for buoyancy.
 22. The ventfor sealing a building crawlspace according to claim 1, furthercomprising a grille, the grille comprising a plurality of openingstherein, the grille positioned near the front end of the vent box andcovering the front end of the vent box, wherein the top box portion ofthe vent box comprises a flap slot near the front end of the vent box,the grille hingably mounted to the vent box with the grille comprising aflexible member near the top of the grille that engages and is heldwithin the flap slot near the front end of the vent box, wherein thegrille is constructed and arranged to pivot within the vent passagewayby the flexible member flexing relative to the remainder of the grille.23. The vent for sealing a building crawlspace according to claim 1,further comprising a grille, the grille comprising a plurality ofopenings therein, the grille positioned near the front end of the ventbox and covering the front end of the vent box, the grille hingablymounted to the vent box and the grille constructed and arranged to pivotwithin the vent passageway, the vent box further comprising a grillechannel, wherein the grille channel receives and seats therein anunattached edge of the grille when the grille is in an at rest, homeposition.
 24. The vent for sealing a building crawlspace according toclaim 1, the vent box further comprising a grille stop near the frontend of the vent box portion, wherein the grille stop is formed by afirst raised member that is raised above the bottom box portion and asecond raised member that is raised above the bottom box portion, andwherein the grille stop receives and seats therein between the firstraised member and the second raised member an unattached edge of theflexible flood flap when the flexible flood flap is in the at rest, homeposition.
 25. The vent for sealing a building crawlspace according toclaim 2, the vent box further comprising a grille stop near the frontend of the vent box portion, wherein the grille stop is formed by afirst raised member that is raised above the bottom box portion and asecond raised member that is raised above the bottom box portion, andwherein the grille stop receives and seats therein between the firstraised member and the second raised member an unattached edge of theflexible flood flap when the flexible flood flap is in the at rest, homeposition.
 26. The vent for sealing a building crawlspace according toclaim 1, the vent box further comprising a grille stop near the frontend of the vent box portion, wherein the grille stop is formed by afirst plurality of spaced apart raised members that are raised above thebottom box portion and a second plurality of spaced apart raised membersthat are raised above the bottom box portion, and wherein the grillestop receives and seats therein between the first plurality of spacedapart raised members and the second plurality of spaced apart raisedmember an unattached edge of the flexible flood flap when the flexibleflood flap is in the at rest, home position.
 27. The vent for sealing abuilding crawlspace according to claim 2, the vent box furthercomprising a grille stop in the rear end of the vent box portion,wherein the grille stop is formed by a first plurality of spaced apartraised members that are raised above the bottom box portion and a secondplurality of spaced apart raised members that are raised above thebottom box portion, and wherein the grille stop receives and seatstherein between the first plurality of spaced apart raised members andthe second plurality of spaced apart raised member an unattached edge ofthe flexible flood flap when the flexible flood flap is in the at rest,home position.